Investigation into Effectiveness of By-pass Cement Dust as Soil Stabilizer in Road Construction

Abstract By-pass cement dust (BPCD) is produced in large amount

Effectiveness of Compaction Grout Piles in Improving Foundation Soils of Existing Runway

Compaction grout piles were used to minimize the liquefaction potential of the foundation soils of Tokyo International Airport at the intersection area of the two runways A and B. The compaction grout piles were intermittent to treat only the liquefiable soil layers and of varying diameter to account for the variable condition of the treated soils. This paper describes the performed grouting works and presents improvement results for one of the grouting stages. The presented results reveal the effectiveness of the adopted design and procedure in improving the liquefiable soils. The paper also discusses the improvement results with emphasis being on the obtained improvements at the vertical boundaries of the treatment zones. The discussion suggests that there is a loss of improvement at the boundaries and this loss is attributed to the boundary effect and the effect of variation of soil compressibility around the boundary of treatment zone. A correlation between a newly presented index called relative compressibility index (RCI) and the improvement at the boundary is identified. This correlation is useful in planning the intermittent treatments by compaction grout piles and implies that the loss of soil improvement at the boundary of treatment zone increases as RCI decreases